148 results about "Differential centrifugation" patented technology

The embodiment of the invention discloses a method for extracting extracellular vesicles from a traditional Chinese medicine dry product. The method comprises the following steps: taking a dry traditional Chinese medicine product as a raw material, and sequentially performing crushing, soaking, first-order enzymolysis, wall breaking, differential centrifugation, second-order enzymolysis, high-speed centrifugation, ultracentrifugation and ultrafiltration enrichment to obtain the extracellular vesicles. A two-step enzymolysis method is adopted in the enzymolysis process, impurities are removed to the maximum extent in a sequence difference enzymolysis mode, and the structure and function stability of the exosome are protected. According to the invention, the differential centrifugation and the enzymolysis method are alternately used, so that impurities with different sizes and different properties can be removed more thoroughly. According to the method, the cost is strictly controlled, the exosome purification efficiency is relatively high, the concentration of the obtained dry exosome is relatively high, and the operability is extremely high.

The invention discloses an implant-derived exosome which is prepared by the following steps: adding cleaned and crushed colored rice flour into a PBS (Phosphate Buffer Solution) with the pH value of 6-7.4, homogenizing at a high speed, adding alpha-amylase into rice milk, performing enzymolysis for 1-2 hours under the conditions that the pH value is 6-7.4 and the temperature is 90-97 DEG C, filtering, and standing filtrate overnight; carrying out gradient differential centrifugation at 4 DEG C, collecting supernate, filtering, carrying out ultracentrifugation on filtrate at 4 DEG C and 12000-15000g for 1.5-3 hours, and collecting precipitate; and re-suspending the precipitate, enriching by using an MWCO ultrafiltration tube with the molecular weight cut-off of 100kDa, collecting the precipitate at the bottom of the ultrafiltration tube, and re-suspending in a PBS buffer solution, thereby obtaining the product. The exosome can effectively inhibit the generation of inflammatory factors, has a good inhibition effect on various pathogenic bacteria, also has an anti-oxidation effect, and has application prospects in the fields of inflammation resistance, bacteria resistance, oxidation resistance and the like.

The present invention discloses a method for extracting a stable body from cyanobacteria, comprising the following steps: S1. Cultivating cyanobacteria; S2. Pretreating cyanobacteria; S3. Ultrasonic disruption; S4. Differential centrifugation; S5. Ultrafiltration; S6. Ultracentrifugation; S7. Density gradient centrifugation; S8. Removing peripheral proteins. The extraction method provided by the present invention has high extraction efficiency, stable and controllable process, no toxic by-products, is green and environmentally friendly, and does not require high temperature and high pressure equipment and large instruments and equipment, thereby expanding application scenarios and reducing application costs. The present invention can obtain high polyP n Stable, active granular biomaterials with high polymerization degree, concentration, and purity, as well as high bioactivity, can meet the stringent requirements of applications in the food and daily chemical sectors, as well as clinical medicine and scientific research. They possess significant practical application value and commercial prospects, and will address the technical challenges of preparing stable, active granular biomaterials in China.

The invention relates to the technical field of biological medicine, in particular to a lactobacillus-sourced extracellular vesicle and application of the lactobacillus-sourced extracellular vesicle in prevention and treatment of necrotizing enterocolitis, the extracellular vesicle is prepared from lactobacillus, the lactobacillus is Lactobacillus rhamnosus GG, the strain is purchased in the American Center for Type Culture Collection, and the preservation number is ATCC 53103. The preparation method of the extracellular vesicles comprises the following steps: carrying out ultracentrifugation on a lactobacillus culture solution, removing thalli, then collecting supernate, carrying out primary microfiltration, taking micro-filtrate, carrying out differential centrifugation, resuspending precipitates by using PBS, then carrying out secondary microfiltration, collecting the micro-filtrate, carrying out density gradient centrifugation, and collecting a 30-45% interface vesicle layer. The invention discloses a synergistic effect mode between intestinal symbiotic flora and intestinal epithelial cell metabolic molecules for the first time, and the discovery is expected to construct a brand-new mechanism normal form for regulating the host intestinal barrier function by flora.

The invention provides a plant exosome as well as an extraction method and application thereof in cosmetics, and belongs to the technical field of exosome extraction. The preparation method of the plant exosome comprises the following steps: mixing plant tissues with a solvent, carrying out high-pressure homogenization treatment, adding immobilized compound enzyme for enzymolysis, filtering, carrying out differential centrifugation on enzymatic hydrolysate, and carrying out size exclusion chromatography and ultrafiltration purification to obtain the plant exosome. Wherein exosome release and protection are considered, and the influence of agglomeration on the exosome extraction effect is avoided; high-pressure homogenization and immobilized compound enzyme enzymolysis are adopted, physical wall breaking is combined with chemical wall breaking, and the yield of the exosome is increased; the immobilized compound enzyme can avoid free enzyme residues, and the subsequent purification step is simplified; the plant exosome can be further purified through size exclusion chromatography and ultrafiltration. The exosome prepared by the method disclosed by the invention can retain the active ingredients of the exosome to the greatest extent, has excellent antioxidant, anti-inflammatory and whitening effects, and is suitable for the field of cosmetics.

The invention belongs to the field of biotechnology and aquaculture, and particularly relates to a method for improving hypoxia resistance of pelteobagrus vachelli based on hypoxia induction of liver extracellular vesicles of the pelteobagrus vachelli. The method comprises the following steps: extracting high-purity extracellular vesicles EVs in liver tissues of pelteobagrus vachelli subjected to low-oxygen treatment by adopting a method of combining differential centrifugation and high-precision iodixanol density gradient centrifugation; diluting the extracted EVs to 2mu g / mu L by using PBS (Phosphate Buffer Solution) to prepare an EVs suspension; an intraperitoneal injection mode is adopted, the EVs suspension is injected into the body of the pelteobagrus vachelli, and after injection is conducted for 24 hours, the hypoxia resistance of the pelteobagrus vachelli is evaluated through a suffocation point detection test. The invention opens up a brand new path for improving the hypoxia resistance of the pelteobagrus vachelli, provides a new idea and a new method for efficiently enhancing the hypoxia resistance of economic fishes in the field of aquaculture, is expected to play an important role in actual aquaculture production, and assists the sustainable development of the aquaculture industry.

The invention relates to an astragaloside-loaded astragalus membranaceus exosome which is prepared by the following steps: crushing astragalus membranaceus, and filtering to obtain juice; performing multi-step differential centrifugation to obtain supernate; carrying out ultrafiltration and centrifugation, and collecting the precipitate; adding to the upper layer of a sucrose stepped gradient solution, centrifuging, and collecting part of strips; after dilution, centrifuging, discarding the supernatant, precipitating, and removing cane sugar to obtain the astragalus membranaceus exosome; the radix astragali exosome loaded with the astragaloside is obtained by mixing the radix astragali exosome with the astragaloside and carrying out ultrasonic treatment or co-incubation, and can be used for preparing medicines for specifically inhibiting cGAS / STING pathway excessive activation in cerebral ischemia reperfusion injury and downstream NLRP3 inflammasome mediated pyroptosis and preparing medicines for protecting and repairing mitochondria in the cerebral ischemia reperfusion injury. The homologous astragalus membranaceus exosome is used as a natural carrier, the blood-brain barrier is effectively overcome, and the enrichment concentration and bioavailability of astragaloside in a cerebral ischemia area are remarkably improved.

The invention discloses a preparation method of vascular tissue-derived extracellular vesicles, and belongs to the field of cytobiology. According to the preparation method of the extracellular vesicles, the artery blood vessel tissue is directly subjected to enzymolysis through collagenase, the extracellular vesicles are obtained by combining low-speed centrifugation and ultra-speed centrifugation methods and utilizing a differential centrifugation mode, and the technical blank of obtaining the extracellular vesicles from the blood vessel tissue is filled. Experimental results show that the extracellular vesicles can be successfully prepared from collagenase I, collagenase II, collagenase IV, collagenase V or collagenase IV combined with elastin, the prepared extracellular vesicles are different in particle size, form, yield, protein quantity, purity and the like, and the quality of the extracellular vesicles obtained by enzymolysis of collagenase IV combined with elastin is optimal. The extracellular vesicles are extracted from vascular tissues with normal physiological characteristics for the first time, a new source is provided for preparation of the extracellular vesicles, and the extracellular vesicles have great significance in expanding application of the extracellular vesicles.

The invention discloses an early-stage lung cancer prediction method based on a multi-modal eccDNA marker, and relates to the technical field of liquid biopsy, and the method comprises the following steps: collecting a peripheral blood sample, carrying out differential centrifugal separation on plasma, constructing a cfDNA library, and carrying out double-end sequencing to obtain original sequencing data; extracting structural features through an eccDNA model, and inputting the structural features into a first machine learning model to generate a circular DNA score; extracting variation features through an SNV model, and inputting the variation features into a second machine learning model to generate a spectrum feature score; extracting copy number features through a CNV model, and inputting the copy number features into a third machine learning model to generate copy number scores; carrying out probability distribution calibration on the circular DNA score, the spectrum feature score and the copy number score; inputting the three types of molecular features into a deep neural network to generate a first fusion score; inputting the calibrated score into a logistic regression model to generate a second fusion score; and generating a final lung cancer risk probability according to the first fusion score and the second fusion score.

The invention discloses a frog skin secretion source exosome, a preparation method and application in skin wound healing, and belongs to the technical field of biological medicine. According to the preparation method of the exosome, frog skin secretions are obtained through an electrical stimulation method, then separation and purification are carried out through a method of combining differential centrifugation and a qEV separation column, and finally the exosome is obtained. The frog skin secretion source exosome provided by the invention shows a remarkable skin wound healing promoting effect in both in-vitro and in-vivo experiments, and shows a remarkable beneficial effect in the field of skin wound healing. And the hydrogel has the advantages of no toxic or side effect and good biocompatibility, provides an efficient and safe novel treatment strategy for skin wound repair, and has a wide functional skin care product or clinical application prospect.

The invention discloses an immune agonist and a preparation method thereof, and relates to the technical field of immune agonist preparation, and the preparation method of the immune agonist comprises the following specific steps: S1, preparing a double-target immune agonist monomer; s2, preparing a cationic liposome inner core; s3, biomimetic cell membrane coating; and S4, finished product detection. According to the immune agonist and the preparation method thereof, in the preparation process, a continuous flow microreactor is used for two-step synthesis of a double-target monomer, a segmented precise temperature control mode is matched with microwave strengthening, the reaction period can be shortened, efficient entrapment of the agonist is achieved through a micro-reaction technology, and the problems that a traditional batch method is low in entrapment efficiency and uneven in particle size are solved; in addition, MDC cell membrane extraction is conducted through differential centrifugation, the integrity of the membrane is guaranteed, active targeting of a CD11c marker on the surface of the MDC cell membrane is achieved through a cell biomimetic membrane, and after lipidosome and membrane vesicles with the volume ratio being 3: 1 are fused, the in-vitro BMDC binding rate is increased compared with that of naked lipidosome.

The invention discloses a purification method of cord blood mesenchymal stem cell source exosome, and relates to the technical field of bioengineering. The method comprises the following steps: firstly, carrying out pH regulation pretreatment on cell culture supernate through a technical path of combining gradient centrifugation and membrane filtration, and sequentially removing cell debris and large-particle impurities by adopting multi-stage differential centrifugation; then carrying out selective protein precipitation by utilizing polyethylene glycol with specific molecular weight, and realizing fine separation of the exosome by combining sucrose-meglumine diatrizoate density gradient centrifugation; and finally, terminal purification is completed under low-temperature and low-pressure conditions through a polyethersulfone membrane filtration system with an optimized pore size. According to the method, centrifugal parameters, reagent concentration and filtering conditions are precisely regulated and controlled, so that the particle size of the obtained exosome is intensively distributed in the range of 30-150nm, the protein purity reaches 95% or above, the recovery rate exceeds 85%, and the separation efficiency and quality of the exosome are remarkably improved.

The invention provides a red ginseng fruit exosome, which is prepared by taking fresh fruits of Campumoea lancifolia (Roxb.) Merr. As raw materials, and extracting the red ginseng fruit exosome by adopting a differential centrifugation method and an ultra-high-speed centrifugation method. The invention also provides a preparation method and application of the exosome. The crataegus pinnatifida fruit exosome has the functions of resisting inflammation, regulating immunity and the like, and can inhibit colitis, improve the intestinal environment and inhibit expression of cell inflammatory factors, so that the effect of relieving ulcerative colitis symptoms is achieved, and a theoretical basis and a scientific basis are provided for treating ulcerative colitis by using the crataegus pinnatifida fruit-sourced exosome.

The invention discloses a composition containing ginseng exosome and super-elastic protein and application of the composition, and belongs to the technical field of biology. The composition containing the ginseng exosome and the super-elastic protein is prepared by compounding the ginseng exosome and the super-elastic protein according to the weight ratio of 10: (100-150), the ginseng exosome is prepared by the following method: extracting the ginseng exosome from ginseng root tissues by using a differential centrifugation method to obtain a ginseng exosome crude extract; adding sucrose solutions with different concentrations into the ginseng exosome crude extract, and performing ultra-high-speed centrifugal purification to obtain purified ginseng exosome; the amino acid sequence of the super-elastic protein is as shown in SEQ ID NO. 3. According to the invention, the ginseng exosome and the super-elastic protein are combined for use for the first time, and both the ginseng exosome and the super-elastic protein have the effect of promoting cell proliferation, so that the use safety is high; the ginseng exosome and the super-elastic protein can synergistically improve the skin tightening and anti-wrinkle effects and the skin injury repairing effect.

The invention belongs to the technical field of thermal interface materials, and particularly relates to a boron nitride-based flexible heat-conducting composite film and a preparation method and application thereof.The preparation method comprises the following steps that h-BN powder and water are mixed and subjected to ball milling, centrifugation is conducted after ball milling, supernate is taken, and BNNS dispersion liquid is obtained; carrying out differential centrifugation on the obtained BNNS dispersion liquid to obtain large-sheet-diameter BNNS, and carrying out uniform ultrasonic dispersion on the large-sheet-diameter BNNS in a differential alcohol organic solvent to obtain large-sheet-layer BNNS organic dispersion liquid; the preparation method comprises the following steps: performing oxidation modification on cellulose nanofibers by adopting a TEMPO oxidation method, and uniformly dispersing the oxidized and modified cellulose nanofibers in water to obtain an aqueous dispersion of the oxidized and modified CNF; the preparation method comprises the following steps: mixing an organic dispersion liquid of large-lamellar BNNS with an aqueous dispersion liquid of oxidation modified CNF, firstly stirring, and then carrying out ultrasonic mixing to obtain a BNNS / CNF composite dispersion liquid; and carrying out suction filtration on the BNNS / CNF composite dispersion liquid to obtain a wet film, and drying and tabletting the wet film to obtain the boron nitride-based flexible heat-conducting composite film. The preparation method is suitable for continuous and large-scale preparation of the high-performance boron nitride-based composite heat-conducting film.

The utility model relates to the technical field of water quality monitoring, and discloses a differential centrifugal device for water quality monitoring, which comprises a bottom plate and a mounting shell, and further comprises a clamping assembly arranged in a containing cavity and used for increasing the loading and unloading speed of a centrifugal tube, the driving assembly is arranged on one side of the mounting shell and can provide rotating force for the transmission shaft. According to the utility model, the synchronous positioning of the centrifugal tubes in the plurality of placing grooves can be realized through the clamping assembly, so that the loading and unloading process of the centrifugal tubes is simplified, the loading and unloading difficulty of the centrifugal tubes is reduced, and the labor burden of detection personnel is relieved; the rotating drum is driven by the driving assembly to rotate to separate and precipitate different substance particles in a water sample, the turbidity test of a water body is completed, the conditions of distortion, breakage and the like of the transmission shaft due to overlarge centrifugal force can be avoided through the limiting assembly, and the stability of the structure is improved.

The invention relates to the technical field of modernization of traditional Chinese medicines, in particular to a nano-vesicle, a preparation method and application of the nano-vesicle in preparation of an endometrial injury repairing medicine. The preparation method comprises the following steps: taking a periplaneta americana ethanol extracting solution, and adding a buffer solution to prepare diluted homogenate; performing differential centrifugal treatment on the homogenate; filtering the supernatant obtained by the differential centrifugation treatment, and then centrifuging for 60-120 minutes by 100000g of the supernatant to obtain a precipitate; and re-suspending the precipitate to obtain the periplaneta americana ethanol extract source nano-vesicles. The periplaneta americana ethanol extract is used as a starting material to enrich the nano-vesicles for the first time, the combined process of differential centrifugation, membrane filtration and ultracentrifugation is adopted, the obtained nano-vesicles can be applied to the field of endometrial injury repair, especially treatment of gynecological diseases such as intrauterine adhesion and infertility with thin intima, and the blank in the technical field is filled.

This invention belongs to the field of biomedical technology, specifically relating to a madder-derived exosome-like nanovesicle, an artificial blood vessel, and their preparation and application. This invention utilizes differential centrifugation and sucrose density gradient centrifugation techniques to extract high-purity, highly active exosome-like nanovesicles from madder. Then, polydopamine is loaded onto the surface of a small-diameter polyurethane artificial blood vessel, which is then immersed in a suspension of madder-derived exosome-like nanovesicles to obtain a small-diameter artificial blood vessel loaded with madder-derived exosome-like nanovesicles. These madder-derived exosome-like nanovesicles can effectively promote endothelial cell proliferation and inhibit reactive oxygen species generation; animal experiments show unobstructed blood flow under ultrasound. The small-diameter artificial blood vessel loaded with madder-derived exosome-like nanovesicles can simultaneously achieve in vivo endothelialization and vascular patency, possessing significant clinical application value.

The invention relates to the technical field of biological medicine, and provides application of a dental pulp stem cell exosome in preparation of a medicine for treating and preventing osteoarthritis, a preparation method of the dental pulp stem cell exosome comprises the following steps: S1, obtaining dental pulp tissue from a dental pulp cavity of an in-vitro tooth; s2, pretreating dental pulp tissues, adding digestive juice, digesting, centrifuging, discarding supernatant, adding a complete culture medium containing antibiotics into precipitates, mixing, filtering and centrifuging to obtain dental pulp stem cells; and S3, culturing the dental pulp stem cells by using a complete culture medium, when the confluence degree of the dental pulp stem cells reaches 60-80%, replacing the serum-free culture medium for continuous culture, collecting the dental pulp stem cell conditioned culture medium, and performing differential centrifugation to obtain the dental pulp stem cell exosome. According to the technical scheme, the regulating effect of the dental pulp stem cell exosome on endoplasmic reticulum stress and the mechanism of the dental pulp stem cell exosome for improving cartilage cell degeneration are explored.

The application belongs to the technical field of cell biology, and particularly relates to a solution rich in Sargassum fusiforme nano-vesicles and a preparation method and application thereof. The solution rich in Sargassum fusiforme nano-vesicles is prepared by a differential centrifugation combined with hollow fiber membrane concentration, and the obtained solution rich in Sargassum fusiforme nano-vesicles can play an anti-inflammatory role, inhibit high-fat diet induced fatty liver and osteoporosis, and can also be used for preparing a mask with soothing, moisturizing and anti-wrinkle effects.

The invention discloses a quercetin nano-vesicle complex as well as a preparation method and application thereof. The preparation method of the nano-vesicles comprises the following steps: separating and purifying extracellular vesicle-like nano-particles from cow milk by combining differential centrifugation with an EDTA precipitation method; quercetin is efficiently loaded in a vesicle nanostructure by adopting an ultrasonic-assisted co-incubation technology, and a drug loading system is characterized through particle size analysis, Zeta potential determination and a transmission electron microscope. The natural lipid bilayer structure of the milk-derived extracellular vesicles is creatively utilized, the constructed quercetin nano-vesicle complex shows excellent stability in simulated gastrointestinal fluid, and the average encapsulation efficiency can reach 60%. In-vitro and in-vivo experiments prove that the nano vesicles can efficiently remove senescent cells. The invention has a wide clinical application prospect in the field of anti-aging and inflammation-related disease treatment.

The present application relates to an activated stem cell microcapsule, a preparation method and application thereof. The activated stem cell microcapsule is prepared by the following method: taking mesenchymal stem cells, culturing the mesenchymal stem cells in a culture medium containing resveratrol, collecting the supernatant, and centrifuging the supernatant by differential centrifugation to obtain the activated stem cell microcapsule; the concentration of the resveratrol in the culture medium is less than 1.5 micromoles per liter. Then the activated stem cell microcapsule is mixed with a nitric oxide donor for incubation to obtain an activated stem cell microcapsule loaded with a nitric oxide donor. The activated stem cell microcapsule and the activated stem cell microcapsule loaded with the nitric oxide donor provided by the present application have good blood vessel repair effect and can be used for preparing a drug for treating peripheral vascular lesions.

The invention discloses application of exosome-like nanoparticles derived from fructus lycii to preparation of a medicine for preventing or treating oligospermia and / or asthenospermia. Sterile, stable and high-purity fructus lycii exosome-like nanoparticles (LBELNs) are obtained by adopting a differential centrifugation-suction filtration-ultra-high-speed centrifugation method, the physiological efficacy of the LBELNs is researched, and it is found that the LBELNs can significantly improve the oligoasthenospermia disease activity index of male mice induced by cyclophosphamide (CTX); the sperm quantity is obviously increased, the sperm malformation is improved, the sperm motility is improved, and the sex hormone level is recovered. The LBELNs can effectively relieve spermatogenic dysfunction of testicular tissues, the sperm differentiation and formation process is obviously improved, the total number of sperms is increased, and the treatment effect is more obvious along with increase of the dosage of the LBELNs. The invention has potential in preparation of drugs for preventing or treating oligoasthenospermia, and provides a new strategy and treatment method for treating oligoasthenospermia.

The invention relates to the technical field of medicines, in particular to an extraction method and application of cordate houttuynia exosome-like nanoparticles. The method comprises the steps of pretreatment, impurity removal through differential centrifugation, fine filtration, ultra-speed centrifugation crude extraction, sucrose density gradient centrifugation purification, washing and the like. By optimizing key process parameters, the HELNs with the average particle size of 50-150nm and the typical double-layer membrane cup-shaped vesicle form can be stably obtained. Experiments prove that the HELNs prepared by the method have independent and direct anti-staphylococcus aureus activity. Based on the newly discovered biological activity, the invention provides new application of the HELNs in preparation of products (such as antibacterial drugs, dressings, coatings, lotions and the like) for inhibiting staphylococcus aureus and / or treating infection of staphylococcus aureus. The method is standard in operation and good in repeatability, and widens the application field of active ingredients of houttuynia cordata.

The invention discloses a stem cell-based microvesicle as well as a preparation method and application thereof, belongs to the technical field of biological tissue engineering, and particularly relates to a preparation method of the stem cell-based microvesicle, which comprises the following steps: culturing stem cells until the cell fusion degree is 80-90%, performing hypoxia treatment, and cleaning for 2-3 times; standing and culturing the cleaned stem cells, then adding a calcium ion carrier, and carrying out ultrasonic treatment; the serum-free basic culture medium containing the calcium ion carrier is immediately absorbed and removed, the cells are cleaned through PBS, culture is conducted for 24 h, and cell supernatant is collected and merged respectively; performing first centrifugation to remove cell debris; performing second centrifugation to remove dead cells and large cell debris; carrying out third centrifugation to remove organelles; fourth centrifugation is carried out, large vesicles are removed, and a final supernatant is obtained; and filtering and centrifuging to obtain a microvesicle precipitate. The preparation method of the microvesicles aims at systematically improving the yield and biological activity of the stem cell microvesicles through low-oxygen pre-stimulation, ultrasonic-calcium ion carrier synergistic induction and differential centrifugation.

The invention discloses a preparation method for industrial production of plant-derived exosomes, and relates to the technical field of biological product preparation. Comprising the following steps: S1, pretreatment of raw materials: cleaning and disinfecting plant tissues, mixing the plant tissues with a buffer solution, and homogenizing to obtain a plant crude extract; s2, pre-clarification: sequentially carrying out differential centrifugation and step-by-step filtration on the crude extract obtained in the step S1 to remove large-particle impurities so as to obtain pre-clarified liquid; s3, tangential flow filtration: performing concentration and buffer solution replacement on the pre-clarified solution through a tangential flow filtration system to obtain a primarily purified exosome concentrated solution. According to the method disclosed by the invention, industrial, continuous and scalable production of the plant exosome is realized, the product purity is high, and the batch difference is small; impurities influencing gelation are removed through an optimized purification process, a method for compounding the exosome with polysaccharide hydrogel under a low shear condition is defined, the formed compound preparation improves the structural stability of the exosome by 2-5 times, and local sustained-release administration is realized.

This invention belongs to the field of ultrasound contrast microbubble synthesis technology, and relates to a method for preparing and applying ultrasound contrast microbubbles targeting CD93 molecules in tumor vascular endothelium. The method includes the following steps: constructing a recombinant expression vector capable of expressing the CD93 ligand MMRN2 protein, transfecting cells, and extracting the cell membrane using differential centrifugation; mixing dipalmitoylphosphatidylcholine, distearate phosphatidylethanolamine-polyethylene glycol 2000, and chloroform, adding DiI, and preparing a liposome membrane using a thin-film hydration method; mixing the cell membrane and the liposome membrane, performing ice-bath sonication, and mixing and shaking with perfluoropropane to obtain an ultrasound contrast agent targeting CD93 molecules in tumor vascular endothelium. The ultrasound contrast microbubbles prepared by the method of this invention have good biocompatibility compared to conventional antibody-targeting strategies, and can also improve stability and targeting, thereby enabling the assessment of CD93 molecule expression in tumors.

The invention discloses an exosome composition containing resveratrol, astragalus membranaceus and ginseng as well as a preparation method and application of the exosome composition, and belongs to the technical field of biological medicines. The exosome composition disclosed by the invention is obtained by inducing alveolar epithelial cells by active ingredients containing resveratrol, an astragalus extract and a ginseng extract and then secreting the alveolar epithelial cells. The preparation method of the exosome composition mainly comprises the following steps: co-culturing the active component and alveolar epithelial cells, and then sequentially carrying out differential centrifugation and ultracentrifugation on the collected cell supernatant to purify the exosome. The invention also provides a pharmaceutical preparation containing the exosome composition. According to the composition, traditional Chinese medicine active ingredients are combined with a modern cell exosome technology, a potential strategy is provided for prevention and treatment of pulmonary fibrosis, and the composition has a good application prospect.

The invention discloses a method for extracting extracellular vesicles of dried coptis chinensis, which comprises the following steps: step 1, taking out the dried coptis chinensis, washing sandy soil with tap water, and immersing the dried coptis chinensis with a phosphate buffer solution for 24 hours; 2, peeling the coptis chinensis in the step 1, juicing with a juicer, and filtering; 3, treating the filtrate in the step 2 by using a differential centrifugation method to obtain a crude extract of the dried coptis chinensis; step 4, carrying out primary purification on the crude extract in the step 3 by using sephadex G25; step 5, carrying out purification treatment of sucrose density gradient centrifugation on the crude extract primarily purified in the step 4 by using an ultra-speed centrifuge to obtain the dried coptis chinensis extracellular vesicles; according to the preparation method, the dry coptis chinensis extracellular vesicles with higher protein content can be successfully prepared, and the tea-support-shaped extracellular vesicles are good in stability and dispersity.

The application discloses a bifendate biomimetic oral nanodelivery system based on lactobacillus helveticus exosomes and a preparation method and application thereof. The preparation method comprises the following steps: extracting lactobacillus helveticus exosomes from a lactobacillus helveticus culture solution by adopting a method combining continuous differential centrifugation and microporous membrane filtration; and mixing the lactobacillus helveticus exosomes with bifendate, and performing ultrasonic treatment and incubation treatment to prepare the lactobacillus helveticus exosome-bifendate biomimetic oral nanodelivery system. The application successfully extracts a lactobacillus helveticus source exosome with high yield and expandable advantages for the first time, and improves the clinical limitations of high cost and low productivity of animal source and plant source exosomes as oral delivery carriers; meanwhile, the prepared lactobacillus helveticus exosome-bifendate biomimetic oral nanodelivery system combines the natural characteristics of exosomes and the high biological safety of probiotics, and can realize the balance between the oral delivery performance and the biological safety of the nanocarrier.